The present invention relates to a valve, in particular a vacuum valve, having at least one valve housing and at least one closure member and at least one valve seat, wherein the valve seat surrounds at least one valve opening of the valve and the closure member is movable back and forth by at least one closure member drive between at least one open position, in which the closure member at least partially clears the valve opening, and a closed position, in which the closure member is pressed against the valve seat by way of a sealing surface of the closure member in order to close the valve opening.
Valves of this type are used in particular as vacuum valves inter alia when production or machining processes have to be carried out in a defined atmosphere under defined pressure conditions and in particular in what is known as a vacuum, that is to say under negative pressure. To this end, the valves can be used to connect chambers, for example process chambers or transfer chambers, together in a closable and pressure-resistant manner. The valve housing of the valves is, in such applications, frequently attached to a chamber wall of the corresponding chamber. Integrated configurations are also possible. The valve opening of the valve is then usually aligned with a corresponding chamber opening. If the closure member is in the open position, the valve opening is at least partially cleared and workpieces to be machined can be introduced into the corresponding chamber or removed therefrom. If the valve is in the closed position, the chamber is sealed off and the conditions, in particular pressure conditions, required for the particular process can be set. Valves of the abovementioned type can also be what are known as metering valves, however, in which the valve is used to meter a fluid, in particular gas, into a chamber or the like.
In order for it to be possible to carry out the particular processes, it is usually very important to reduce, or at best entirely prevent, the introduction, creation and transport of undesired particles as far as possible.